Magnetically-triggered proximity switches, also known as limit switches, are commonly used for linear position sensing. Examples of such magnetically-triggered proximity switches are described in U.S. Pat. No. 8,362,859, the entirety of which is incorporated by reference herein.
Magnetically-triggered proximity switches typically detect the presence and/or proximity of a target without physically contacting the target. When the target, which may include, for example, a ferrous object or a permanent magnet contained in a housing, is beyond a specified range of the proximity switch, a magnetic flux associated with a bias magnet that is non-movably positioned in the proximity switch causes a detector magnet that is movably positioned in the proximity switch to be drawn toward the bias magnet, which places the proximity switch in a first switch position. In the first switch position, a normally open circuit of the proximity switch is open, and a normally closed circuit of the proximity switch is closed.
When the target passes within the specified range of the proximity switch, a magnetic flux associated with the target triggers and/or causes the detector magnet of the proximity switch to be drawn toward the target and away from the bias magnet, which places the proximity switch in a second switch position. In the second switch position, the normally open circuit of the proximity switch is closed, and the normally closed circuit of the proximity switch is open.